DNA sequencing is in the throes of an enormous technological shift marked by dramatic throughput increases, a precipitously dropping per-base cost of raw sequence, and an accompanying requirement for substantial investment in large capital equipment in order to utilize the technology. Investigations that were, for most, unreachable luxuries just a few years ago (individual genome sequencing, metagenomics studies, and the sequencing of myriad organisms of interest) are being increasingly enabled, at a rapid pace.
Genetic information in living organisms is contained in the form of very long nucleic acid molecules such as deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Naturally occurring DNA and RNA molecules are typically composed of chemical building blocks called nucleotides, bound together by a phosphate backbone, which are in turn made up of a sugar (deoxyribose or ribose, respectively), and one of four bases, adenine (A), cytosine (C), guanine (G), and thymine (T) or uracil (U). The human genome, for example, contains approximately three billion nucleotides of DNA sequence and an estimated 20,000 genes. DNA sequence information can be used to determine multiple characteristics of an individual as well as the presence of or susceptibility to many common diseases, such as cancer, cystic fibrosis, and sickle cell anemia. Determination of the entire three billion nucleotide sequence of the human genome has provided a foundation for identifying the genetic basis of such diseases. A determination of the sequence of the human genome required years to accomplish. Sequencing the genomes or sections of the genome of individuals provides an opportunity to personalize medical treatments. The need for nucleic acid sequence information also exists in research, environmental protection, food safety, biodefense, and clinical applications, such as for example, pathogen detection, i.e., the detection of the presence or absence of pathogens or their genetic variants.
Thus, because DNA sequencing is an important technology for applications in bioscience, such as, for example, the analysis of genetic information content for an organism, tools that allow for faster and or more reliable sequence determination are valuable. Applications such as, for example, population-based biodiversity projects, disease detection, personalized medicine, prediction of effectiveness of drugs, and genotyping using single-nucleotide polymorphisms, stimulate the need for simple and robust methods for sequencing short lengths of nucleic acids (such as, for example, those containing 1-20 bases performed with specific primers. Sequencing methods that provide increased accuracy and or robustness, decreased cost, reduced input sample, and or high throughput are valuable analytical and biomedical tools.
Additionally, molecular detection platforms that have a reduced capital cost, are miniaturized and manufacturable in high volumes provide access to affordable disease detection to many people in places and situations in which such access was not in the past possible. The availability of affordable molecular diagnostic devices reduces the cost of and improves the quality of healthcare available to society. Additionally, portable molecular detection devices have applications in security and hazard detection and remediation fields and offer the ability to immediately respond appropriately to a perceived security or accidental biological or chemical hazard.
However, many improvements are still needed in the area of DNA sequencing and DNA sequencing detection.